In:
New Phytologist, Wiley, Vol. 197, No. 2 ( 2013-01), p. 454-467
Abstract:
Strawberry ( F ragaria × ananassa ) fruits contain high concentrations of flavonoids. In unripe strawberries, the flavonoids are mainly represented by proanthocyanidins ( PA s), while in ripe fruits the red‐coloured anthocyanins also accumulate. Most of the structural genes leading to PA biosynthesis in strawberry have been characterized, but no information is available on their transcriptional regulation. In A rabidopsis thaliana the expression of the PA biosynthetic genes is specifically induced by a ternary protein complex, composed of A t TT 2 ( A t MYB 123), A t TT 8 ( A tb HLH 042) and A t TTG 1 ( WD 40‐repeat protein). A strategy combining yeast‐two‐hybrid screening and agglomerative hierarchical clustering of transcriptomic and metabolomic data was undertaken to identify strawberry PA regulators. Among the candidate genes isolated, four were similar to AtTT2 , AtTT8 and AtTTG1 ( FaMYB9 / FaMYB11 , FabHLH3 and FaTTG1 , respectively) and two encode putative negative regulators ( FaMYB5 and FabHLH3∆ ). Interestingly, FaMYB9 / FaMYB11 , FabHLH3 and FaTTG1 were found to complement the tt2‐1 , tt8‐3 and ttg1‐1 transparent testa mutants, respectively. In addition, they interacted in yeast and activated the A rabidopsis BANYULS (anthocyanidin reductase) gene promoter when coexpressed in P hyscomitrella patens protoplasts. Taken together, these results demonstrated that FaMYB9 / FaMYB11 , FabHLH3 and FaTTG1 are the respective functional homologues of AtTT2 , AtTT8 and AtTTG1 , providing new tools for modifying PA content and strawberry fruit quality.
Type of Medium:
Online Resource
ISSN:
0028-646X
,
1469-8137
DOI:
10.1111/nph.2012.197.issue-2
Language:
English
Publisher:
Wiley
Publication Date:
2013
detail.hit.zdb_id:
208885-X
detail.hit.zdb_id:
1472194-6
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